It is known to monitor wear in crimping machines. To assess the wear of a crimping tool in EP 0 419 129 B1, for example, dimensional changes in the crimping press are detected with the aid of an extensometer and compared to a range of acceptable crimping forces for a specific crimping level. Where a specific crimping force is no longer achieved as a result of wear, an adjustment signal is output which prompts a readjustment of the crimp contacts.
A readjustment signal for crimping pliers is known from DE 10 2004 009 489 A1 in which the crimping punch that acts on the crimp contacts is brought into the crimping position by a swivel piston guided in a curved body. A selected presetting of the crimping pliers is indicated by an electronic display. However, if the crimp stamp or the curved body become worn, then the display of the value for the presetting will contain an error.
DE 296 02 238 U1 shows a testing device for testing crimping devices or parts supporting the press jaws thereof. The crimping device or a part thereof must be placed in a specific position in the testing device. During the testing procedure empty crimping is carried out, whereby after the crimping force is applied the gap width between two opposing end faces of adjoining crimping jaws is measured. The gap width is displayed to the operator in order for the latter to decide whether the crimping device can continue to be used or not. This solution is suitable only for crimping devices in which the crimping jaws essentially impact one another when the crimping device is actuated or with which only a single degree of crimping is realized.
The document DE 200 12 887 U1 displays a device for testing the wear on crimping pliers. This device comprises a test element that includes an indicator which is to be arranged between the end faces of the crimping jaws when an object is crimped. The indicator is compressed to less than a predetermined comparatively small gap width. This solution is also only suitable for crimping pliers in which the crimping jaws essentially impact one another when the crimping device is actuated or with which only a single degree of crimping can be realized.
EP 2 025 475 A2 describes a pressing device for joining workpieces and a method for performing a technical diagnosis of the pressing device. Information representing the number of strokes and at least one piece of operating information per operating second of the drive are continually stored in an information memory of the device. Operating information of the drive, for example, in the form of the power input of the electric motor or pressure measurement data of an electrohydraulic drive and/or the force measurement data in the area of the pressing tool are stored as operating information. Additional stored data may include the temperature and/or date or period of operation of the drive. Based on the stored information, it is possible to subsequently analyze the operation of the pressing device in order, for example, to determine gradually occurring wear, so that, if necessary, prognoses can be made on the number of pressing operations that can still be successfully executed.
A pair of crimping pliers is known from US 2008/0276678 A1 which comprise a force sensor, a position sensor, a data processing unit and a display. The quality of the crimping result can be indicated on the display by colored LEDs (red, green).
A method and a device for monitoring the wear on a pair of hand pliers is known from DE 10 2009 026 470 A1, in which the degree of crimping is adjustable by means of a presetting device. In this device a reference setting of the presetting device is first detected in which the crimping elements are not yet subject to wear. Measurement of the wear status of the presetting device is repeated after being activated a specific number of times. Wear cannot be detected and precise standard crimping cannot be assured, if the wear measurement is not carried out by the user in the predetermined intervals.